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Structural Health Monitoring System for High-rise and Unique Buildings
Andrey Shakhramanyan, PhD; Joost Kuckartz; Yury A. Kolotovichev, PhD NPO SODIS, LLC Moscow, Russia
Abstract—An automated system for building structural monitoring is developed. The system allows for real-time condition and status information of a building. Through the sensory equipment different building parameters are obtained and processed in a special software package.
The software package is based upon mathematical model rules, which for the most critical components set limits for structural safety. The mathematical model is verified with real-time measurements and consequently used in the real-time structural modeling system.
Keywords – high-rise buildings, monitoring systems, mathematical modelling, BIM, structural health monitoring, software.
I. INTRODUCTION There are many new high-rise and unique buildings in
Russia, including the Sochi Olympic venues (Sochi-2014) and FIFA 2018 World Cup stadiums. Strengthened security and safety requirements caused changes in the regulations and laws for the design and monitoring process of high-rise buildings. Several documents were approved by the Russian Government and are now national standards and federal laws. NPO SODIS is one of the main participants in the development of these national Russian standards for building monitoring and safety.
According to the Russian laws and standards each high-rise and unique building must be monitored by a monitoring system. There are two types of monitoring systems; a structural monitoring system and an infrastructure monitoring system for building services. This article focuses on the first only (see also [1]).
Structural monitoring systems are a common subject in research, as it is the main tool for obtaining structural parameters. The reasons for structural monitoring systems however are shifting from simply obtaining structural parameters for evaluation to a more user-centric based monitoring system for maintenance and safety [2].
Since 2005 NPO SODIS has actively been designing and installing structural and infrastructure monitoring systems on Olympic venues in Sochi, stadiums for the FIFA World Cup 2018, high-rise buildings of Moscow-City center and many others. The total number of projects with monitoring systems designed by NPO SODIS exceeds 200. With a special software
package the monitoring system is focused on maintenance and safety – and is for the user.
II. STRUCTURAL MONITORING SYSTEM
A. System Architecture The structural monitoring system consists of sensors
located at carefully selected positions throughout the building, data transmission equipment and a server for data collection and control. Within the server analysis software containing a special mathematical model is present. The server connects to a local operator desktop application and can remotely be viewed and updated (Figure 1. ). The operator can monitor the building in real-time and immediately see the status of the building.
Figure 1. System architecture
B. System Development Process The system development process contains three
stages: design, construction and maintenance: • In the design stage threats are modeled, the required
monitoring parameters are identified and mathematical and computer models are generated. In this stage initial rules are set up which determine the sensor type and location. Depending on the required parameter, sensors can be installed embedded in the concrete, on an armature or in special housings.
• In the construction stage sensors and other equipment is installed in the building. By monitoring the building for a period of time and evaluating the results, the mathematical and computer models developed in the design stage are verified and corrected in the monitoring software when needed.
• The maintenance stage is where the building operators take control of the monitoring system and use the specially developed software for building operation and maintenance. The software allows the operators to immediately see the status of the building.
The main working principles of the system are as follows (Figure 2. ). The sensors installed on a building’s structure record monitoring parameters corresponding to construction elements identified critical to the building’s safety. For each monitored parameter (such as deformation, frequency, inclination, pressure and others) normative values are obtained based on the mathematical model of the building. As the mathematical model has been corrected to the initial state to the building in the construction stage, differences between measured and normative values allows decision making about the building’s state and conditions. These results, including the ability to view the raw data, are displayed to the building operator.
Figure 2. Main working principles
Figure 3. SODIS Building M interface
III. SODIS BUILDING M SOFTWARE FOR STRUCTURAL MONITORING
A special structural monitoring software package, SODIS Building M, is developed and marketed by NPO SODIS. This software allows the structural monitoring system to make complex analysis of different measurements and display the monitored results in real time.
The software package is used to define the complicated rules obtaining the building status. After this definition, the software is used in the operation of the structural monitoring system by making decisions on the real-time state or condition of the building. Each building requires its own mathematical model, its own set of rules and the software is therefore tailored to each building.
For the operator of the building, the software can work with 2D and 3D models of buildings and structures. It is able to show all available sensors, the corresponding data of these sensors and all diagnostic messages coming from the system. Most importantly it immediately issues warning messages if the rules of the mathematical model are exceeded, therefore allowing to immediately identify safety concerns of the building (Figure 3. ).
A. Building Information Model (BIM) SODIS Building M is based on a BIM model of a
building (Figure 4. ), containing the building's structural elements, monitoring system sensor locations, but also the monitored parameters and the technical status of the building. Direct access to the sensor data from a particular sensor is accessible through navigation in the program and the BIM model.
Figure 4. BIM model of the ‘Maly’ ice arena in Sochi (Olympic venue for
SOCHI-2014)
Figure 5. Detection and control of changes of the natural resonance frequency in an automatical mode in SODIS Building M
B. Mathematical Model A building’s status is the result of the comparison of
the calculated values of the monitored parameters with the results of the mathematical modeling. Usually ANSYS, Robot or other commercial structural simulation packages are used to develop mathematical models, which are then used in the monitoring system. The results of the mathematical modeling are used in the knowledge base of SODIS Building M (as shown in Figure 1. ).
C. Data Collection and Processing Modules For monitoring in real time SODIS Building M
contains special drivers, which allow the reception of data from any type of sensors (strain gauges, accelerometers, tiltmeters, temperature gauges, etc.) and special modules for the calculation of monitored parameters. Ошибка! Источник ссылки не найден. shows an example of natural resonance frequency detection for one of the structural elements and the automatic control of its change.
D. Module for Setting Rules of Estimating Building Status SODIS Building M has tools for setting complex
rules, which are used by the system to estimate the current status of a building. These rules are set up with an “and/or”
principle with the plurality of conditions of the monitored parameters values comparison with the normative ones.
IV. EXAMPLE STRUCTURAL MONITORING APPLICATION Structural health monitoring systems designed by
NPO SODIS are used for high-rise building, stadiums, tunnels and bridges ([1]). Almost all stadiums of the Sochi 2014 Olympic winter games have a structural monitoring system installed. The Ice arena ‘Maly’, as shown in Figure 4. , was one of the first to have the monitoring system installed and three earthquake events were recorded during its construction period.
During the design of the monitoring system, two main axes of deformation of the roof were identified. To track its deformation, 8 digital 3-axis accelerometers were installed for dynamic monitoring (Figure 6. ) and 8 digital 2-axis tiltmeters were installed to measure inclination of the foundation (Figure 7. ).
Figure 6. Installation locations of 3-axis accelerometers on the trusses of the ‘Maly’ ice arena. Accelerometer number 8 is installed at the foundation plate.
Figure 7. Installation locations of 3-axis tiltmeters on the foundation plate of
the ‘Maly’ ice arena.
From 19/11/2012 until 28/01/2013, while construction was ongoing, corrections to the estimated values of the controlled parameters were made. This is to combat the deviation between the mathematical model results from simulations and real, as-built construction. This model updating based on real measurements is a very important task, as the as-built model will be the foundation for the long-term monitoring and detection of anomalies.
Figure 8. shows the inclination of the baseplate in the X axis as calculated from sensor No. 5. Although a lot of outliers are shown, these can be explained by the high sensitivity of the sensor and the ongoing construction; they are therefore likely to have occurred because of construction equipment. The figure does however identify the foundation settlement inclination.
Figure 8. Inclination of the base plate in the X axis as calculation from
sensor no. 5.
Figure 9. Accelerograph of the M5.7 earthquake recorded at the base plate.
Figure 10. Accelerograph of the M5.7 earthquake recorded at the roof truss
(sensor no. 5).
During this period, three earthquakes were recorded: an M4.9 on 10/12/2013 230 km northwest of the building’s location, an M5.7 on 23/12/2012 170km southeast and M5.2 on 25/12/2012 170km southeast. The M5.7 earthquake caused the largest vibrational response, as shown in Figure 9. and Figure 10. . In the comparison of both responses, a magnification of vibrational amplitude of approximately 8 can be identified between base slab and roof truss.
V. CONCLUSION This paper described an automated, real-time
monitoring system for high-rise and unique buildings. This system includes specialist software for real-time operation of the system and uses a building information model for user access. A monitored stadium is given as an example, which during the prescribed monitoring period measured three earthquakes.
REFERENCES
[1] Andrey SHAKHRAMANYAN, Joost KUCKARTZ, Yuri A. KOLOTOVICHEV, Modern Structural Monitoring Systems for High-Rise and Unique Buildings. CSHM-4, November 2012, Berlin, Germany.
[2] Kuckartz, J., Collier, P. (2011), A User-centric Approach to the Design of Structural Health Monitoring Systems. In proceedings of the Joint International Symposium on Deformation Monitoring, November 2011, Hong Kong, China.
